Fix "height only VitalSign" restriction on FamilyHistory

@p2 noticed that this restriction references spcode:VitalSign when it
should actually reference sp:VitalSign.  I initially created the
restriction using the "Class expression editor" and Protégé decided that
"VitalSign" meant spcode:VitalSign and not sp:VitalSign.  I
used the "Object restriction creator" to explicitly specify
sp:VitalSign.

(chb/smart_project_management#125)